There have been many approaches to provide a small light associated with personal use keys. These allow the keyhole to be illuminated at night making it easy to find and insert the key. The most common type are separate lights attached to a key chain. The light is turned on and aimed at the keyhole. The appropriate key at the other end of the chain is then used. This is however a two hand operation and simply takes extra time plus these lights, though miniaturized, are usually relatively large, cumbersome to carrying around, aren't very bright and often look hokey. There have also been key holders with lights, light mechanisms that attach to the side of keys and factory produced keys with a light integrated into a plastic top. These are typically large, expensive or are only available if you purchase a luxury car. None of these meet the need to provide a method to easily add a very small, inexpensive, one hand use light to virtually any existing house, car or other key.